merc120_81
Petty Officer 3rd Class
- Joined
- Jun 20, 2011
- Messages
- 92
Hello All,
40 year sailer, newbie power boater.
Power is a Mercruiser MCM120 (I4 153ci) sn/5828###, stearn drive pretty sure, alpha.
she can idle/run slow all day(150/160F), but when I get on her to pull the kids on a tube, the temp climbs way too high (reads over near 210/220)
Purchased an infrared/laser temp probe as suggested in the forums, gauge is probably off, atleast 20 degrees. I have also purchased a generic temp gauge and sending unit to get an engine water temp with somthing new next time I am out.
Where should I point the laser dot on the IR probe, and what temps should I be seeing?
thermastat housing?
cylhead between the plugs?
temp sending unit?
Waterbox/exhuast/elbow/riser?
out hose to waterbox/exhaust/elbow/riser??
How likely is it that he circulation pump on this boat could be bad?
There is some pretty heavy corrosion when I take off the "U" shaped large cooling hose on the starbord side/front of the engine (my best guess, cyl head to water pump)
I have not done a test for impeller function with any measurement (bucket and running exactly at I believe it was 650rmp) but have pulled the cold water in, off, and it seems to be spitting quite a bit of water (underway idling on the lake).
I have replaced the sterndrive impleller, and thermostat. Impeller replacement was a kit, included gaskets, uperhousing, o rings, impeller. the old houseing was in decent condition a few scratches in the cup, but that was about it.
Running freshwater in Michigan, water temps around 65 to 70 F.
thank you.
40 year sailer, newbie power boater.
Power is a Mercruiser MCM120 (I4 153ci) sn/5828###, stearn drive pretty sure, alpha.
she can idle/run slow all day(150/160F), but when I get on her to pull the kids on a tube, the temp climbs way too high (reads over near 210/220)
Purchased an infrared/laser temp probe as suggested in the forums, gauge is probably off, atleast 20 degrees. I have also purchased a generic temp gauge and sending unit to get an engine water temp with somthing new next time I am out.
Where should I point the laser dot on the IR probe, and what temps should I be seeing?
thermastat housing?
cylhead between the plugs?
temp sending unit?
Waterbox/exhuast/elbow/riser?
out hose to waterbox/exhaust/elbow/riser??
How likely is it that he circulation pump on this boat could be bad?
There is some pretty heavy corrosion when I take off the "U" shaped large cooling hose on the starbord side/front of the engine (my best guess, cyl head to water pump)
I have not done a test for impeller function with any measurement (bucket and running exactly at I believe it was 650rmp) but have pulled the cold water in, off, and it seems to be spitting quite a bit of water (underway idling on the lake).
I have replaced the sterndrive impleller, and thermostat. Impeller replacement was a kit, included gaskets, uperhousing, o rings, impeller. the old houseing was in decent condition a few scratches in the cup, but that was about it.
Running freshwater in Michigan, water temps around 65 to 70 F.
thank you.